Lichen isn’t a single organism, but a combination of fungi and algae or cyanobacteria. These organisms exist in a symbiotic, mutually beneficial relationship. The algae or cyanobacteria photosynthesise - producing food via the sun’s rays, which feeds the fungus. The fungus gathers nutrients and environmental moisture, passing it back to the algae or cyanobacteria.

Lichen come in many shapes, sizes, forms and colour, are found on surfaces where other organisms struggle to survive, such as rocks, roofs, driveways, asphalt and tree bark. It thrives on tree bark which is exposed to harsh sunlight and rain. It can also be found on plants with sparse foliage, which allow the lichen access to the sun and moisture it needs to grow.

Not always welcome in the garden, they do not actually harm the plants that they grow on. Lichens are a beneficial plant to the ecosystem, they provide food, shelter and nesting material for many bird and animal species.

Lichen do not like pollution so are a sign that the surrounding air is of good quality.

Prevention

Regular cleaning of exposed paths, driveways, roofs, or older structures on your property can help keep Lichen at bay.

Feed and water plants well, as plants with sparse foliage can provide the ideal environment for Lichen.

You can gently scrub a trees bark to remove lichen with a clean moist rag or loofa, as their ‘roots’ do not penetrate the bark. Do this with care, as you do not want to take any of the bark off.

Treatment on Trees

In late autumn and winter you can use Lime Sulphur to remove lichen on deciduous trees only. Do not use it on evergreens, as they will defoliate (lose their leaves) and will not recover.

Take care if using this product as it can stain paths and fences.

When using sprays and chemicals always read the label and follow instructions carefully. Spray in the evening to avoid harming beneficial insects.

Treatment on Surfaces

To control Lichen on hard surfaces such as walls, driveways, paths and roofs use Yates Surrender.

Do not use these products on roofs that have a collection water system.